Refrigerator

ABSTRACT

A refrigerator is provided. The refrigerator includes a refrigerator includes a compressor configured to compress a refrigerant, a condensing unit configured to pass the compressed refrigerant and a first heat exchanger unit and a second heat exchanger unit where each of the first heat exchanger unit and the second heat exchanger unit are configured to provide heat exchange as the refrigerant passes therethrough. When a defrosting mode is performed for one of the first heat exchanger unit and the second heat exchanger unit, the refrigerant compressed at the compressor unit is supplied to the one of the first heat exchanger unit and the second heat exchanger unit, and then the refrigerant is supplied to the other one of the first heat exchanger unit and the second heat exchanger unit after the refrigerant is passed through an expansion valve.

CROSS REFERENCE TO RELATED APPLICATION

Pursuant to 35 U.S.C. §119(a), this application claims the benefit of the Korean Patent Application No. 10-2012-0067111, filed on Jun. 22, 2012, which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND OF THE DISCLOSURE

1. Field of the Disclosure

The present invention relates to refrigerators, and more particularly, to a refrigerator which can reduce power consumption of the refrigerator at the time of defrosting an evaporator.

2. Discussion of the Related Art

In general, the refrigerator, used for frozen or refrigerated storage of food, is provided with a case which forms partitioned spaces defining a freezing chamber and a refrigerating chamber. In addition, the refrigerator includes a compressor, a condenser, an evaporator, a capillary tube, and so on for forming a refrigerating cycle to lower temperatures of the freezing chamber and the refrigerating chamber.

The case has a door mounted to one side thereof for opening/closing the freezing chamber and the refrigerating chamber.

The refrigerator performs refrigerating operation with a refrigerating cycle in which low temperature and low pressure gaseous refrigerant is compressed to high temperature and high pressure gaseous refrigerant by the compressor, the high temperature and high pressure gaseous compressed refrigerant is turned to high pressure liquid refrigerant as the high temperature and high pressure gaseous refrigerant passes through the condenser, the high pressure liquid refrigerant undergoes temperature and pressure drops as the high pressure liquid refrigerant passes through a capillary tube, and the refrigerant having the temperature and pressure dropped thus cools down air around the evaporator as the refrigerant is turned to low temperature and low pressure gaseous refrigerant while absorbing heat from the air around the evaporator.

If a related art refrigerator forms frost at the evaporator, a heater adjacent to the evaporator is used to defrost the evaporator. However, defrosting using the heater causes a problem in that power consumption of the heater increases refrigerator power consumption. In addition, if the heater is operated excessively to introduce the heat from the heater to the refrigerating chamber or the freezing chamber, it is necessary to drive the compressor again for running the refrigerating cycle to once again reduce the temperature in the refrigerating chamber or the freezing temperature, which requires consumption of additional energy.

SUMMARY OF THE DISCLOSURE

To solve the problems, an object of the present invention is to provide a refrigerator which has no heater for defrosting the evaporator.

Another object of the present invention is, to provide a refrigerator which can reduce power consumption of the refrigerator in defrosting, more particularly, to provide a refrigerator which enables to run a refrigerating cycle by using energy consumed for defrosting.

Additional advantages, objects, and features of the disclosure will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a refrigerator includes a compressor unit for compressing refrigerant, a condensing unit for passing the refrigerant compressed thus, and a first heat exchanger unit and a second heat exchanger unit each for making heat exchange as the refrigerant passes therethrough, wherein, if a defrosting mode is performed for one of the first heat exchanger unit and a second heat exchanger unit, the refrigerant compressed at the compressor unit is supplied to one of the first heat exchanger unit and the second heat exchanger unit, and then the refrigerant is supplied to the other one of the first heat exchanger unit and the second heat exchanger unit after the refrigerant is passed through an expansion valve.

In this case, if the defrosting mode is performed for the first heat exchanger unit, heat can be supplied to the first heat exchanger unit by the refrigerant, and cold can be supplied to the second heat exchanger.

In this case, if the defrosting mode is performed for the second heat exchanger unit, heat can be supplied to the second heat exchanger unit by the refrigerant, and the cold can be supplied to the first heat exchanger.

In the meantime, if the defrosting mode is performed, the refrigerant can pass through an expansion valve between the first heat exchanger unit and the second heat exchanger unit.

Especially, if the defrosting mode is performed, one of the first heat exchanger unit and the second heat exchanger unit can become a high temperature part having a relatively high temperature, and the other one of the first heat exchanger unit and the second heat exchanger unit can become a low temperature part having a relatively low temperature.

And, if the defrosting mode is performed, the refrigerant which does not pass through the condensing unit can pass through one of the first heat exchanger unit and the second heat exchanger unit.

In a cold supply mode on the first heat exchanger unit, the refrigerant passed through the condensing unit can be introduced to the first heat exchanger unit after passing through the expansion valve.

In the cold supply mode on the second heat exchanger unit, the refrigerant passed through the condensing unit can be introduced to the second heat exchanger unit after passing through the expansion valve.

Especially, in the cold supply mode, the refrigerant can be introduced to one of the first heat exchanger unit and the second heat exchanger unit selectively after the refrigerant passes through the condensing unit.

In the meantime, the first heat exchanger unit can be provided for supplying the cold to a refrigerating chamber, and the second heat exchanger unit can be provided for supplying the cold to a freezing chamber.

The compressor unit can include a first compressor unit for supplying the refrigerant to the first heat exchanger unit in the cold supply mode, and a second compressor unit for supplying the refrigerant to the second heat exchanger unit.

In the defrosting mode on the first heat exchanger unit, the second compressor unit can supply the refrigerant in order of the first heat exchanger unit and the second heat exchanger unit, and, in the defrosting mode on the second heat exchanger unit, the first compressor unit can supply the refrigerant in order of the second heat exchanger unit and the first heat exchanger unit.

Opposite to this, the second heat exchanger unit can be provided with a cold accumulation unit having a phase change material placed therein, and the cold accumulation unit can be provided to supplement the cold to the freezing chamber or the refrigerating chamber.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a further understanding of the invention, illustrate embodiments of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 illustrates a diagram showing a state where a cold supply mode is performed in accordance with an exemplary embodiment of the present invention;

FIG. 2 illustrates a diagram showing a state for implementing a defrosting mode of a second heat exchanger unit in FIG. 1 is performed;

FIG. 3 illustrates a diagram showing a state for implementing a defrosting mode of a first heat exchanger unit in FIG. 1 is performed;

FIG. 4 illustrates a diagram showing a state where a cold supply mode is performed in accordance with another exemplary embodiment of the present invention;

FIG. 5 illustrates a diagram showing a state for implementing a defrosting mode of a second heat exchanger unit in FIG. 4 is performed;

FIG. 6 illustrates a diagram showing a state for implementing a defrosting mode of a first heat exchanger unit in FIG. 4 is performed; and

FIG. 7 illustrates a diagram showing a state where a cold supply mode is performed in accordance with another exemplary embodiment of the present invention.

DESCRIPTION OF SPECIFIC EMBODIMENTS

Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

For convenience and clarity of description, a size or a shape of an element shown in the drawing may be exaggerated. Terms specially defined taking a configuration and operation of the present invention into account may vary with intentions or usual practices of the user and operator. It is required that definition on such terms is made with reference to entire description of the present invention.

A word of “cold” used in this specification as a noun has a meaning opposite to a word of “heat” used as a noun which means warmth or hotness.

FIG. 1 illustrates a diagram showing a state where a cold supply mode is performed in accordance with an exemplary embodiment of the present invention.

Referring to FIG. 1, the refrigerator includes a compressor unit 10 for compressing the refrigerant, a condensing unit 20 for passing the compressed refrigerant, and a first heat exchanger unit 24 and a second heat exchanger unit 28 for making heat exchange as the refrigerant passes therethrough.

In the meantime, a plurality of pipelines connect various valves, the condensing unit 20, the compressor unit 10, the first heat exchanger unit 24, and the second heat exchanger unit 28 to allow movement of refrigerant.

In this exemplary embodiment, the compressor unit 10 may include a first compressor unit 12 for supplying the refrigerant to the first heat exchanger unit 24 and a second compressor unit 14 for supplying the refrigerant to the second heat exchanger unit 28 in a cold supply mode.

The cold supply mode is a regular refrigerator operation state in which the cold is supplied to an inside of the refrigerator through the first heat exchanger unit 24 or the second heat exchanger unit 28. In the cold supply mode of the first heat exchanger unit 24, the cold is supplied to the inside of the refrigerator through the first heat exchanger unit 24, and, in the cold supply mode of the second heat exchanger unit 28, the cold is supplied to the inside of the refrigerator through the second heat exchanger unit 28.

The first heat exchanger unit 24 may be provided to supply the cold to the refrigerating chamber, and the second heat exchanger unit 28 may be provided to supply the cold to the freezing chamber. That is, the refrigerating chamber may be cooled by the cold supplied from the first heat exchanger unit 24, and the freezing chamber may be cooled by the cold supplied from the second heat exchanger unit 28. The first heat exchanger unit 24 may be an element matched to a refrigerating chamber evaporator and the second heat exchanger unit 28 may be an element matched to a freezing chamber evaporator. In this case, the first compressor unit 12 may be driven when the cold is supplied to the refrigerating chamber evaporator, which is the first heat exchanger unit 24, and the second compressor unit 14 may be driven when the cold is supplied to the freezing chamber evaporator, which is the second heat exchanger unit 28.

A system for implementing a cold supply mode in which the cold is supplied to the refrigerating chamber will be described. If the refrigerant is compressed by the first compressor unit 12, the refrigerant is guided to the condensing unit 20 by a first three-way valve 30. Heat exchange of the refrigerant occurs at the condensing unit 20. Then, the refrigerant may pass through an expansion valve 22 for the first heat exchanger unit by the second three-way valve 32, and be guided to the first heat exchanger unit 24. That is, since heat exchange occurs at the first heat exchanger unit 24, the cold can be supplied to the refrigerating chamber through the first heat exchanger unit 24. The refrigerant passing through the first heat exchanger unit 24 may be guided to the first compressor unit 12 to implement the refrigerating cycle.

It is possible that the cold supply mode in which the cold is supplied to the refrigerating chamber has a concept the same with the cold supply mode of the first heat exchanger unit 24. In the cold supply mode of the first heat exchanger unit 24, the refrigerant passing through the condensing unit 20 is introduced to the first heat exchanger unit 24 after the refrigerant passes through the expansion valve 22 for the first heat exchanger unit.

Next, a system for implementing the cold supply mode in which the cold is supplied to the freezing chamber will be described. If the refrigerant is compressed by the second compressor unit 14, the compressed refrigerant can pass the first compressor unit 12 without any change. Of course, the compressed refrigerant at the second compressor unit 14 may be further compressed at the first compressor unit 12. In this case, since the refrigerant is compressed at the second compressor unit 14 and the first compressor unit 12 in succession, a compression load on the second compressor unit 14 can be reduced. Moreover, since the refrigerant is compressed at the second compressor unit 14 and the first compressor unit 12, a compression performance can be improved.

The refrigerant passes through the condensing unit 20 by the first three-way valve 30. The refrigerant may be guided to the expansion valve 26 for the second heat exchanger unit and forwarded to the second heat exchanger unit 28 by the second three-way valve 32. Since heat exchange occurs at the second heat exchanger unit 28, the cold can be supplied to the freezing chamber. The refrigerant passing through the second heat exchanger unit 28 may be guided to the second compressor unit 14 again to implement the refrigerating cycle.

It is possible that the cold supply mode in which the cold is supplied to the freezing chamber has a concept the same with the cold supply mode of the second heat exchanger unit 28. In the cold supply mode of the second heat exchanger unit 28, the refrigerant passing through the condensing unit 20 is introduced to the second heat exchanger unit 28 after the refrigerant passes through an expansion valve 26 for the second heat exchanger unit.

That is, in the embodiment described with reference to FIG. 1, since a flow path of the refrigerant can be guided by the second three-way valve 32, the cold can be supplied to the freezing chamber or the refrigerating chamber by the second three-way valve 32. In the cold supplied mode, the refrigerant passing through the compressor unit 10 may be introduced to any one of the first heat exchanger unit 24 or the second heat exchanger unit 28 after the refrigerant passes through the condensing unit 20, selectively.

FIG. 2 illustrates a diagram showing a state for implementing a defrosting mode of a second heat exchanger unit according to the exemplary embodiment shown in FIG. 1.

Referring to FIG. 2, if the second heat exchanger unit 28 is frosted, defrosting of the second heat exchanger unit 28 can be performed.

In this mode, the first compressor unit 12 is put into operation to compress the refrigerant. The compressed refrigerant is guided to the second heat exchanger unit 28 through the first three-way valve 30. In this case, in order to allow the refrigerant to move from the first three-way valve 30 to the second heat exchanger unit 28, a pipeline is connected between the first three-way valve 30 and the second heat exchanger unit 28.

After passing through the first three-way valve, the refrigerant guided to the second compressor unit 28 is at a relatively high temperature because the refrigerant does not pass through the expansion valve before the refrigerant passes through the second heat exchanger unit 28. Since the refrigerant compressed at the first compressor unit 12 has a reduced volume, the refrigerant has an increased temperature. Therefore, as heat is supplied to the second heat exchanger unit 28, the second heat exchanger unit 28 can be heated to a relatively high temperature. As a result, ice stuck to the second heat exchanger unit 28 can be melted to defrost the second heat exchanger unit 28.

In the meantime, the refrigerant passing through the second heat exchanger unit 28 is guided to the first heat exchanger unit 24 after passing through a check valve 36. The refrigerant passes the expansion valve 22 for the first heat exchanger unit before the refrigerant passes through the first heat exchanger unit 24. Therefore, the refrigerant is changed at the expansion valve 22 for the first heat exchanger unit to enable the refrigerant to supply the cold to the first heat exchanger unit 24. The refrigerant can cool the refrigerating chamber connected to the first heat exchanger unit 24 as the refrigerant passes through the first heat exchanger unit 24.

That is, the refrigerator of the present invention puts the first compressor unit 12 into operation to compress the refrigerant for defrosting the second heat exchanger unit 28. However, since the cold is supplied to the first heat exchanger unit 24 by using the compressed refrigerant, a space in communication with the first heat exchanger unit 24 can be cooled. In other words, since the refrigerator of the present invention utilizes energy for defrosting the second heat exchanger unit 28 for implementing the refrigerating cycle of the first heat exchanger unit 24, energy efficiency can be improved. The refrigerator of this exemplary embodiment can use the energy, not only for defrosting, but also for supplying the cold to other parts.

In addition, while defrosting for the second heat exchanger unit 28 is performed, though the first heat exchanger unit 24 becomes a relatively low temperature part, the second heat exchanger unit 28 becomes a relatively high temperature part.

FIG. 3 illustrates a diagram showing a state for implementing a defrosting mode of a first heat exchanger unit in FIG. 1 is performed.

Referring to FIG. 3, if the first heat exchanger unit 24 is frosted, defrosting of the first heat exchanger unit 24 can be performed.

In this mode, the second compressor unit 14 is put into operation to compress the refrigerant. The compressed refrigerant is not passed through the first compressor unit 12, but is guided to the first heat exchanger unit 24. Since the first compressor unit 12 is not in operation, the refrigerant compressed at the second compressor unit 14 cannot pass the first compressor unit 12, but can move to the first heat exchanger unit 24.

The refrigerant guided to the first heat exchanger unit 24 is at a relatively high temperature state because the refrigerant does not pass through the expansion valve before the refrigerant passes through the first heat exchanger unit 24. Since the refrigerant compressed at the first compressor unit 12 has a reduced volume, the refrigerant has an increased temperature. Therefore, as heat is supplied to the first heat exchanger unit 24, the first heat exchanger unit 24 can be heated to a relatively high temperature. As a result, ice stuck to the first heat exchanger unit 24 may be melted to defrost the first heat exchanger unit 24.

In the meantime, the refrigerant passing through the first heat exchanger unit 24 is guided to the second heat exchanger unit 28. In this case, the refrigerant passes through a first two-way valve 34 mounted to a pipeline which is connected between the first heat exchanger unit 24 and the expansion valve 26 for the second heat exchanger unit. The first two-way valve 34 opens a flow passage for the refrigerant to pass through. The refrigerant passes through the expansion valve 26 for the second heat exchanger unit before the refrigerant passes through the second heat exchanger unit 28. Therefore, the refrigerant is changed at the expansion valve 26 for the second heat exchanger unit for the refrigerant to supply the cold to the second heat exchanger unit 28. The refrigerant can cool down the freezing chamber connected to the second heat exchanger unit 28 as the refrigerant passes through the second heat exchanger unit 28.

That is, the refrigerator according to this exemplary embodiment puts the second compressor unit 14 into operation to compress the refrigerant for defrosting the first heat exchanger unit 24. However, since the cold is supplied to the second heat exchanger unit 28 by using the compressed refrigerant, a space in communication with the second heat exchanger unit 28 can be cooled. In other words, since the refrigerator of the present invention utilizes energy for defrosting the first heat exchanger unit 24 for implementing the refrigerating cycle on the second heat exchanger unit 28, energy efficiency can be improved. The refrigerator of this exemplary embodiment can use the energy, not only for defrosting, but also for supplying the cold to other parts.

In addition, while defrosting for the first heat exchanger 24 is performed, though the second heat exchanger unit 28 becomes a relatively low temperature part, the first heat exchanger unit 24 becomes a relatively high temperature part.

When the defrosting mode is performed, and since the refrigerant passes through the expansion valve between the first heat exchanger unit 24 and the second heat exchanger unit 28, the refrigerator of this exemplary embodiment can supply the cold from the first heat exchanger unit 24 or the second heat exchanger unit 28 to which the refrigerant is introduced after the refrigerant passes through the relevant expansion valve.

In the meantime, if defrosting is performed, and since the refrigerant which does not pass through the condensing unit 20 passes through one of the first heat exchanger unit 24 and the second heat exchanger unit 28, the refrigerator of the present invention can defrost the first heat exchanger unit 24 or the second heat exchanger unit 28.

FIG. 4 illustrates a diagram showing a state where a cold supply mode is performed in accordance with another exemplary embodiment of the present invention.

The refrigerator in accordance with this second exemplary embodiment is different from the first exemplary embodiment described above because only a single compressor unit is provided. As a result, in order to change over flow passages through which the refrigerant moves, a plurality of valves are provided in a system that is different from the system according to the first exemplary embodiment; however, the systems are similar in that the various valves and elements are connected with pipelines through which the refrigerant can move.

For convenience's sake, description of features that are identical to the refrigerator in accordance with the first exemplary embodiment of the present invention described above will be omitted. Accordingly, the description made in the refrigerator in accordance with the first exemplary embodiment of the refrigerator may also be applied to the refrigerator in accordance with this second exemplary embodiment.

A cold supply mode will be described, in which the cold is supplied to the first heat exchanger unit 24. The refrigerant compressed by the compressor unit 10 is guided to the condensing unit 20 through a four-way change over valve 40. Then, the refrigerant is guided to the first heat exchanger unit 24 through a third three-way valve 42. The refrigerant passes through the expansion valve 22 for the first heat exchanger unit before the refrigerant moves to the first heat exchanger unit 24. According to this, the cold can be supplied to an inside of the refrigerator through the first heat exchanger unit 24.

The refrigerant passing through the first heat exchanger unit 24 is guided to the compressor unit 10 through a second two-way valve 44. In this case, the second two-way valve 44 opens a flow passage of a pipeline connected between the first heat exchanger unit 24 and the compressor unit 10. Opposite to this, a third two-way valve 48 connected between the compressor unit 10 and the second heat exchanger unit 28 closes a passage of a pipeline. According to this, the refrigerant is not guided to the pipeline having the third two-way valve 48 mounted thereto, but guided to the compressor unit 10 to provide a refrigerating cycle.

In the meantime, a cold supply mode will be described, in which the cold is supplied to the second heat exchanger unit 28. The refrigerant compressed by the compressor unit 10 is guided to the condensing unit 20 through the four-way change over valve 40. Then, the refrigerant is guided to the second heat exchanger unit 28 through the third three-way valve 42. The refrigerant passes through the expansion valve 26 for the second heat exchanger unit before the refrigerant moves to the second heat exchanger unit 28. According to this, the cold can be supplied to an inside of the refrigerator through the second heat exchanger unit 28.

The refrigerant passing through the second heat exchanger unit 28 thus is guided to the compressor unit 10 through the third two-way valve 48. In this case, the third two-way valve 48 opens a flow passage of a pipeline connected between the second heat exchanger unit 28 and the compressor unit 10. Opposite to this, the second two-way valve 44 connected between the compressor unit 10 and the first heat exchanger unit 24 closes a passage of a pipeline. According to this, the refrigerant is not guided to the pipeline having the second two-way valve 44 mounted thereto, but guided to the compressor unit 10 to embody a refrigerating cycle, finally.

In the meantime, in a cold supply mode for supplying the cold to the first heat exchanger unit 24 or the second heat exchanger unit 28, it is provided that a fourth two-way valve 46 mounted to a pipeline connected between the first heat exchanger unit 24 and the expansion valve 26 for the second heat exchanger unit closes a flow passage of the pipeline.

FIG. 5 illustrates a diagram showing a state for implementing a defrosting mode of a second heat exchanger unit in FIG. 4 is performed.

Referring to FIG. 5, the refrigerant compressed at the compressor unit 10 is guided to the second heat exchanger unit 28 after passing through the four-way change over valve 40. In this case, the refrigerant does not pass through the expansion valve 26 for the second heat exchanger unit and the condensing unit 20 before the refrigerant is guided to the second heat exchanger unit 28. Since the refrigerant compressed at the compressor unit 10 moves, the second heat exchanger unit 28, having heat transferred thereto, can be heated to a high temperature, relatively.

The refrigerant is guided to a pipeline having a check valve 49 mounted thereto. In this case, since the third two-way valve 48 mounted to the pipeline connected between the second heat exchanger unit 28 and the compressor unit 10 closes the flow passage, the refrigerant is not guided to the pipeline having the third two-way valve 48 mounted thereto.

After passing through the check valve 49, the refrigerant is guided to the first heat exchanger unit 24 through the expansion valve 22 for the first heat exchanger. In this case, since the refrigerant emits the cold, the first heat exchanger unit 24 can supply the cold. Since the second two-way valve 44 opens a flow passage, the refrigerant is guided to the compressor unit 10 after passing through the second two-way valve 44. Opposite to this, since the third two-way valve 48 is arranged to close the flow passage, the refrigerant is not guided to the third two-way valve 48, but is lead to the compressor unit 10. Similar to above, the fourth two-way valve 46 mounted to a pipeline connected between the first heat exchanger unit 24 and the expansion valve 26 for the second heat exchanger unit closes the flow passage for preventing the refrigerant from flowing to the pipeline.

In the defrosting mode of the second heat exchanger unit, while the second heat exchanger unit 28 becomes the high temperature part since the second heat exchanger unit 28 has a relatively high temperature, the first heat exchanger unit 24 becomes the low temperature part since the first heat exchanger unit 24 has a relatively low temperature. Therefore, ice and the like stuck to the second heat exchanger unit 28 can be removed.

In order to defrost the second heat exchanger unit 28, the compressor unit 10 is put into operation, and, the cold can be supplied to the first heat exchanger unit 24 by using the refrigerant compressed by the compressor unit 10. According to this, energy efficiency can be improved.

FIG. 6 illustrates a diagram showing a state for implementing a defrosting mode of a first heat exchanger unit in FIG. 4 is performed.

Referring to FIG. 6, the refrigerant compressed by the compressor unit 10 is guided to the first heat exchanger unit 24 by the four-way change over valve 40. The refrigerant does not pass through the condensing unit 20 or the expansion valve 22 for the first heat exchanger unit before the refrigerant is guided to the first heat exchanger unit 24.

The second two-way valve 44 mounted to the pipeline connected between the first heat exchanger unit 24 and the compressor unit 10 closes the flow passage. Opposite to this, the fourth two-way valve 46 mounted to the pipeline connected between the first heat exchanger unit 24 and the expansion valve 26 for the second heat exchanger unit opens the flow passage. According to this, the refrigerant is guided, not to pass through the second two way valve 44, but to pass the fourth two-way valve 46.

After passing through the expansion valve 26 for the second heat exchanger unit, the refrigerant is guided to the second heat exchanger unit 28. In the meantime, the third two-way valve 48 connected between the compressor unit 10 and the second heat exchanger unit 28 opens the third two-way valve 48. The refrigerant passing through the second heat exchanger unit 28 is guided to the compressor unit 10 through the pipeline having the third two-way valve 48 mounted thereto.

In the defrosting mode of the first heat exchanger unit, while the first heat exchanger unit 24 becomes the high temperature part since the first heat exchanger unit 24 has a relatively high temperature, the second heat exchanger unit 28 becomes the low temperature part since the second heat exchanger unit 28 has a relatively low temperature. Therefore, ice and the like stuck to the first heat exchanger unit 24 can be removed.

In order to defrost the first heat exchanger unit 24, the compressor unit 10 is put into operation, and, the cold can be supplied to the second heat exchanger unit 28 by using the refrigerant compressed by the compressor unit 10. According to this, energy efficiency can be improved.

FIG. 7 illustrates a diagram showing a state where a cold supply mode is performed in accordance with another exemplary embodiment of the present invention.

Different from the refrigerator in accordance with an exemplary embodiment of the present invention in FIG. 1, the refrigerator in accordance with another exemplary embodiment of the present invention in FIG. 7 includes a cold accumulation unit 60 in the second heat exchanger unit 28. In this case, to make cold accumulation, the cold accumulation unit 60 may have a PCM (Phase Change Material) placed therein.

The PCM has a phase changing from liquid to gas, from solid to gas, or from gas to solid at a certain temperature. Even though a material shows no temperature change at a melting point or a boiling point, since the material absorbs or discharges much energy for changing the state of the material, the PCM can be used for storage of energy within a particular temperature range.

At first, a cold supply mode for supplying the cold to the first heat exchanger unit 24 will be described. The compressor unit 10 is put into operation to compress the refrigerant, and the compressed refrigerant is guided to the condensing unit 20 through a fourth three-way valve 50. Then, after passing through the expansion valve 22 for the first heat exchanger unit, the refrigerant is guided to the first heat exchanger unit 24 to supply the cold thereto. Then, the refrigerant is guided to the compressor unit 10 through a fifth three-way valve 52 to embody the refrigerating cycle.

Next, a cold supply mode for supplying the cold to the second heat exchanger unit 28 will be described. The compressor unit 10 is put into operation to compress the refrigerant, and the compressed refrigerant is guided to the condensing unit 20 through the fourth three-way valve 50. Then, the refrigerant is guided to the first heat exchanger unit 24 after passing through the expansion valve 22 for the first heat exchanger unit to supply the cold thereto. Then, after passing through the fifth three-way valve 52, the refrigerant is guided to the expansion valve 26 for the second heat exchanger unit. After passing through the expansion valve 26 for the second heat exchanger unit, the refrigerant moves to the second heat exchanger unit 28. Therefore, the refrigerant supplies the cold to the second heat exchanger unit 28, too.

In this case, since the second heat exchanger unit 28 is in contact with the cold accumulation unit 60, the cold can be accumulated at the cold accumulation unit 60.

In the meantime, the cold accumulation unit 60 may be provided to the freezing chamber or the refrigerating chamber.

For an example, if the cold accumulation unit 60 is provided to the refrigerating chamber, the second heat exchanger unit 28 may be mounted to the refrigerating chamber, to supply the cold to the refrigerating chamber. In this case, different from the second heat exchanger unit 28, the first heat exchanger unit 24 may be mounted to the freezing chamber for supplying the cold to the freezing chamber. Since the cold accumulation unit 60 is mounted to the refrigerating chamber, if the refrigerating cycle is not in operation by the compressor unit 10, the cold accumulated at the cold accumulation unit 60 may be supplied to the refrigerating chamber.

Opposite to this, the cold accumulation unit 60 may be provided to the freezing chamber. In this case, it is possible that the second heat exchanger unit 28 supplies the cold to the cold accumulation unit 60 for storage of the cold therein. Of course, it is also possible to cool down the freezing chamber with the cold supplied from the second heat exchanger unit 28. In this case, the first heat exchanger unit 24 may be mounted, to the refrigerating chamber for supplying the cold to the refrigerating chamber, or to the freezing chamber for supplying the cold to the freezing chamber.

Since the cold accumulation unit 60 is mounted to the freezing chamber, if the refrigerating cycle is not in operation by the compressor unit 10, the cold accumulated at the cold accumulation unit 60 may be supplied to the freezing chamber.

A defrosting mode of the first heat exchanger unit 24 in accordance with another exemplary embodiment of the present invention will be described.

The refrigerant compressed by the compressor unit 10 is guided to the first heat exchanger unit 24 through the fourth three-way valve 50. In this case, the refrigerant guided to the first heat exchanger unit 24 does not pass through the condensing unit 20 and the expansion valve 22 for the first heat exchanger unit. According to this, the first heat exchanger unit 24 may form the high temperature part which has a relatively high temperature.

Since the first heat exchanger unit 24 is heated to the relatively high temperature, the ice stuck thereto can be melted to remove the ice therefrom. According to this, the defrosting on the first heat exchanger unit 24 can be achieved.

The refrigerant passing through the first heat exchanger unit 24 is guided to the expansion valve 26 for the second heat exchanger unit through the fifth three-way valve 52. Then, the refrigerant may be guided to the second heat exchanger unit 28 to supply the cold to the second heat exchanger unit 28. In this case, since the refrigerant supplies the cold to the second heat exchanger unit 28, the second heat exchanger unit 28 can form the low temperature part which has a relatively low temperature.

As has been described, the refrigerator of the present invention can reduce power consumed during defrosting of the evaporator.

Moreover, the refrigerator of the present invention can improve energy efficiency of the refrigerator because a refrigerating cycle can be embodied by utilizing energy consumed for performing the defrosting.

Moreover, the refrigerator of the present invention permits to supply the cold to one of the refrigerating chamber and the freezing chamber while defrosting the other one of the refrigerating chamber and the freezing chamber.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. 

What is claimed is:
 1. A refrigerator comprising: a compressor configured to compress a refrigerant; a condensing unit configured to pass the compressed refrigerant; and a first heat exchanger unit and a second heat exchanger unit, each of the first heat exchanger unit and the second heat exchanger unit being configured to provide heat exchange as the refrigerant passes therethrough, wherein the refrigerator is configured such that, when a defrosting mode is performed for one of the first heat exchanger unit and the second heat exchanger unit, the refrigerant compressed at the compressor unit is supplied to the one of the first heat exchanger unit and the second heat exchanger unit, and then the refrigerant is supplied to the other one of the first heat exchanger unit and the second heat exchanger unit after the refrigerant is passed through an expansion valve.
 2. The refrigerator as claimed in claim 1, wherein, when the defrosting mode is performed for the first heat exchanger unit, heat is supplied to the first heat exchanger unit by the refrigerant and cold is supplied to the second heat exchanger.
 3. The refrigerator as claimed in claim 1, wherein, when the defrosting mode is performed for the second heat exchanger unit, heat is supplied to the second heat exchanger unit by the refrigerant and the cold is supplied to the first heat exchanger.
 4. The refrigerator as claimed in claim 1, wherein, when the defrosting mode is performed, the refrigerant passes through an expansion valve between the first heat exchanger unit and the second heat exchanger unit.
 5. The refrigerator as claimed in claim 1, wherein, when the defrosting mode is performed, the one of the first heat exchanger unit and the second heat exchanger unit becomes a high temperature part having a relatively high temperature, and the other one of the first heat exchanger unit and the second heat exchanger unit becomes a low temperature part having a relatively low temperature.
 6. The refrigerator as claimed in claim 1, wherein, when the defrosting mode is performed, the refrigerant which does not pass through the condensing unit passes through the one of the first heat exchanger unit and the second heat exchanger unit.
 7. The refrigerator as claimed in claim 1, wherein, in a cold supply mode of the first heat exchanger unit, the refrigerant passing through the condensing unit is introduced to the first heat exchanger unit after passing through the expansion valve.
 8. The refrigerator as claimed in claim 1, wherein, in the cold supply mode of the second heat exchanger unit, the refrigerant passing through the condensing unit is introduced to the second heat exchanger unit after passing through the expansion valve.
 9. The refrigerator as claimed in claim 1, wherein, in the cold supply mode, the refrigerant is introduced to one of the first heat exchanger unit and the second heat exchanger unit, selectively, after the refrigerant passes through the condensing unit.
 10. The refrigerator as claimed in claim 1, wherein the first heat exchanger unit is provided for supplying the cold to a refrigerating chamber, and the second heat exchanger unit is provided for supplying the cold to a freezing chamber.
 11. The refrigerator as claimed in claim 1, wherein the compressor unit includes: a first compressor unit configured to supply the refrigerant to the first heat exchanger unit in the cold supply mode, and a second compressor unit configured to supply the refrigerant to the second heat exchanger unit.
 12. The refrigerator as claimed in claim 11, wherein, in the defrosting mode of the first heat exchanger unit, the second compressor unit supplies the refrigerant to the first heat exchanger unit and then to the second heat exchanger unit.
 13. The refrigerator as claimed in claim 11, wherein, in the defrosting mode of the second heat exchanger unit, the first compressor unit supplies the refrigerant to the second heat exchanger unit and then to the first heat exchanger unit.
 14. The refrigerator as claimed in claim 1, wherein the second heat exchanger unit includes a cold accumulation unit having a phase change material placed therein.
 15. The refrigerator as claimed in claim 14, wherein the cold accumulation unit is provided to supplement the cold to a freezing chamber or a refrigerating chamber of the refrigerator.
 16. A refrigerator comprising: a compressor configured to compress refrigerant; a condensing unit configured to pass the compressed refrigerant; and a first heat exchanger unit and a second heat exchanger unit, each of the first heat exchanger unit and the second heat exchanger unit being configured to provide heat exchange as the refrigerant passes therethrough, wherein the refrigerator is configured such that, when a defrosting mode is performed for one of the first heat exchanger unit and the second heat exchanger unit, refrigerant having a relatively high temperature is supplied to the one of the first heat exchanger unit and the second heat exchanger unit and refrigerant having a relatively low temperature is supplied to the other one of the first heat exchanger unit and the second heat exchanger unit.
 17. The refrigerator as claimed in claim 16, further comprising a storage chamber, wherein cold is supplied to the storage chamber through the first heat exchanger unit or the second heat exchanger unit to which the refrigerant having the relatively low temperature is supplied.
 18. The refrigerator as claimed in claim 16, wherein, when one of the first heat exchanger unit and the second heat exchanger unit requires defrosting relative to the other one of the first heat exchanger unit and the second heat exchanger unit, the refrigerant moves from the compressor unit to the one of the first heat exchanger unit and the second refrigerator unit prior to moving to the other one of the first heat exchanger unit and the second refrigerator unit.
 19. The refrigerator as claimed in claim 16, wherein the defrosting of the first heat exchanger unit or the second heat exchanger unit is performed by the refrigerant compressed at the compressor unit.
 20. A refrigerator comprising: a compressor configured to compress refrigerant; a condensing unit configured to pass the compressed refrigerant; and a first heat exchanger unit and a second heat exchanger unit, each of the first heat exchanger unit and the second heat exchanger unit being configured to provide heat exchange as the refrigerant passes therethrough, wherein the refrigerator is configured such that a flow direction of the refrigerant through each of the first heat exchanger unit and the second heat exchanger unit during a cold supply mode is the same direction as a flow direction of the refrigerant through each of the first heat exchanger unit and the second heat exchanger unit during a defrosting mode. 